Kids in Hong Kong can solve this logic puzzle in 20 seconds, but it completely stumps adults

First grade students in Hong Kong breezed through this puzzle in 20 seconds, but it has us stumped. Or at least it did before we looked up the answer!

Although the puzzle was invented two decades ago, it recently appeared on an elementary school entrance exam in Hong Kong, and has since gone viral.

The puzzle can be found on, and both the Guardian and Daily Mail have reported on the trending mind game. 

Can you solve it?



The key is to not get caught up in complicated calculations or algebra. And not to think so hard!

Remember, children just look at things differently, and sometimes even more simply, without the baggage of all those years of life us adults have shouldered. 

Although children taking the elementary school enterance exam successfully solved the puzzle in the allotted time, adults across the world are scratching their heads.